SAN FRANCISCO (Reuters) - A U.S. federal court considering whether a California ban on gay marriage denies constitutional rights was told on Monday that gays and lesbians have strong political allies, including California's governor and the state's Democratic Party.
Monday was the first day that proponents of Proposition 8 -- a ballot initiative backed by voters in 2008 that ended gay marriage in California -- called witnesses to the stand.
A key question in the case is whether government, and U.S. voters, have a reasonable justification for denying same-sex marriage, such as promoting healthier families, or if the bans instead reflect discrimination and hatred.
Supporters of the ban sought to show through Monday's testimony that gays are not systematically discriminated against.
Prop 8 supporters called as their first witness Kenneth Miller, an associate professor of government at Claremont McKenna College, who was questioned about the political clout of gays and lesbians in the California and federal political systems.
The landmark trial, which began two weeks ago, has included plaintiffs' witnesses testifying that same-sex couples can be good parents, that their health and wealth could rise when married -- benefiting the government as well -- and that gays have a history of persecution.
The United States is divided on same-sex marriage. It is legal in only five states, though most of those, and the District of Columbia, approved it last year.
Two gay men and two lesbian women have asked the federal court to rule that the right to marry has no exceptions under the U.S. Constitution. It is a fight some are betting will go all the way to the U.S. Supreme Court in a bid to overturn bans on same-sex marriage in 40 states.
Supporters of traditional marriage are seeking to show that gays and lesbians have ample political power, with key politicians backing their goals, including same-sex marriage.
District Judge Vaughn Walker said he would admit Miller's testimony after the defense sought to undermine his expert status, noting that in Miller's earlier deposition he did not recognize the names of individuals and organizations who pioneered the gay rights movement in the mid-19th century.
Miller testified that he was surprised by the deep pockets tapped by the same-sex marriage proponents during their "No on Proposition 8" campaign.
"It was striking to me the amount of money raised on both sides of the election," Miller said. "Forty-three million dollars was raised and spent by the opponents of Prop 8 which exceeded very large expenditures by the 'Yes on 8' Campaign."
"For a social issue, this is exceptional," he added.
Miller testified that political allies of gays and lesbians include the Democratic Party, organized labor, elected officials, celebrities, newspapers and corporations from Google to Yahoo -- "the 'Who's Who' of Silicon Valley," he said.
Miller detailed a list of key politicians in the state who support gay and lesbian rights, including Governor Arnold Schwarzenegger -- who opposed Proposition 8 and declined to defend it against the federal constitutional challenge -- and San Francisco Mayor Gavin Newsom, calling him a "nationally recognized" supporter of same-sex marriage.
Moreover, newspapers in California overwhelmingly supported same-sex marriage, with 21 out of California's 23 largest papers endorsing a "No on Proposition 8" position. Two did not take a stand.
"There was no major newspaper in California that took a Yes on Proposition 8 position," Miller told the court.
On cross examination, attorney David Boies sought to undermine Miller's contention that gays and lesbians wield power, exacting an acknowledgement that no high-level California politicians are openly homosexual, that gays are expelled from the U.S. military if they reveal their sexuality and that gay couples in some states cannot adopt children.
Boies is the prominent attorney who argued for Vice President Al Gore in the contentious Bush v Gore U.S. Supreme Court case in 2000 that put George W. Bush in the White House. In defending the rights of gays to marry, he has teamed up with Ted Olson, who argued for Bush in the case that settled the 2000 presidential election.
Editing by Eric Walsh and Cynthia Osterman